import os, glob, random, shutil

MP3Files = []

for root, dirs, files in os.walk("D:\Music"):
    [MP3Files.append(element) for element in glob.glob(root+"\\*.mp3")]

for i in range(0,200):
    myFile = MP3Files.pop(random.randint(0,len(MP3Files)-1))
    print("Copying "+myFile)
    shutil.copyfile(myFile, "D:\\Music\\temp\\"+os.path.basename(myFile))